#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> pii;
const int N = 2e5 + 2;


int n, cnt[N], val[N], mrg;
bool bio[N];
vector<int> adj[N];
priority_queue<pii, vector<pii>, greater<pii> > pq;

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);

    cin >> n;
    for (int i = 1; i < n; ++i) {
        int u, v;
        cin >> u >> v, --u, --v;
        adj[u].push_back(v);
        adj[v].push_back(u);
        ++cnt[u];
        ++cnt[v];
    }
    for (int i = 0; i < n; ++i) {
        val[i] = 1;
        if (cnt[i] == 1) pq.push({1, i});
    }
    while (!pq.empty()) {
        int node = pq.top().second; pq.pop();
        bio[node] = 1;
        int par = -1;
        for (int x : adj[node]) {
            if (bio[x]) continue;
            par = x;
        }
        if (par == -1 || val[par] < val[node]) break;
        val[par] += val[node];
        --cnt[par];
        ++mrg;
        if (cnt[par] == 1) pq.push({val[par], par});
    }
    if (mrg == n - 1) cout << "YES\n";
    else cout << "NO\n";

    return 0;
}